Solo playthrough of Free Ride USA: Can I Visit Every City?

About Free Ride USA, from BoardGameGeek:

During the 1950s, the network of railway lines in USA was modernized because of new diesel locomotives. This allowed people to travel to the major cities to visit beautiful old and new structures worth to see. In Free Ride USA, you are taking charge of rebuilding the railway lines and carry passengers to the cities. Your railway lines and state-owned railway lines are free of charge, while you must pay fellow players to convert their lines into state-owned railway lines. Choose travel routes from an open display of city cards and gain additional coins for the long east-west connections. Visit as many different cities of America as possible to gain the most victory points. Free Ride USA also offers a difficult solo challenge!